This invention relates to the detection of Mycoplasma pneumoniae in humans.
Mycoplasma are distinct from bacteria; they are smaller, completely lack a cell wall, and contain only about 1/6th the amount of DNA that bacteria have. Like bacteria, many mycoplasma can cause diseases of humans, other animals and plants. However, the diseases are often difficult to treat with antibacterial agents due to the inherent resistance of mycoplasma to antibiotics which affect cell walls such as the penicillins. In addition, the detection of mycoplasma in diseased hosts by standard microbiological techniques is often difficult because many types cannot be grown in culture.
Many human diseases are associated with mycoplasmal infection, including: primary atypical pneumonia, non-gonococcal urethritis, chorioamnionitis, low birth weight, pelvic inflammatory disease, postabortal fever, postpartum fever and pyelonephritis. In some cases a causal relationship has been proven between mycoplasma and the disease.
It has been said that Mycoplasma pneumoniae causes from 5% to 20% of all human pneumonias. In closed populations, such as college students and military personnel, the rate is even higher, about 20% to 45%. M. pneumoniae cannot be isolated from the blood of infected patients, but can be isolated from the nose, throat, sputum and trachea. However, only about 10.sup.3 to about 10.sup.5 colony forming units per swab of M. pneumoniae are found in such specimens and they are difficult to culture and slow growing.
M. pneumoniae grow best anaerobically on an extremely complex medium, containing enriched peptone, yeast extract and horse serum. These are not the standard conditions used in a clinical microbiology laboratory, so M. pneumoniae often goes undetected. Furthermore, even if optimized conditions are used, the organisms still require a 10 to 14 day incubation period. These factors make standard serological and sugar fermentation tests impractical as tools for clinical diagnosis.
The routine antibiotic therapy for human pneumonia involves penicillin or ampicillin, which are ineffective in killing mycoplasma; however, there are effective antibiotics, such as erthyromycin, which can control mycoplasma infections. Therefore, there is a need for a clinical diagnostic method capable of rapidly detecting Mycoplasma pneumoniae in infected humans so that a proper course of antibiotic therapy may be chosen promptly.